Electronic devices have become almost ubiquitous in many parts of the world. Computers, televisions, and stereos are common in many areas. Additionally, mobile electronic devices are also becoming more common, including portable computers, portable stereos, and portable televisions. Mobile handsets, sometimes referred to as mobile phones are another example of the multitude of different electronic devices available.
Many electronic devices have other external electronic devices attached to them. One example is a mobile wireless device with a hands-free car kit attached. A hands-free car kit is a device that allows a mobile handset user to talk during a mobile call without having to hold the mobile handset near the user's head.
When connecting one electronic device to another, in many cases, is advantageous to minimize the number of connections between the devices. To illustrate, an example of a mobile handset and a hands-free car kit will be discussed, however, it will be clear that other examples are possible. Many mobile electronic devices can benefit by decreasing the number of connections between each mobile electronic device. Additionally, other examples of electronic devices that are not portable are possible.
Now, returning to the specific example, a mobile handset and a hands-free car kit is described. As stated above, the cost of connectors can, in some cases increase when the number of connections increases. Additionally, connectors with more connections are typically larger than a similarly constructed connector with fewer pins. For these reasons it may generally be advantageous to decrease the number of connections between two electronic devices.
Another problem with electronic devices is that in some cases noise can be caused by the amount of current that flows between two devices. The current flow is in some cases variable. This variable current can cause signal levels in the devices to vary. As a specific example, when one device provides power to a second device the voltage level of a ground reference may vary due to the changing current in the conductor connecting the two devices. In many cases noise can adversely effect the performance of electronic devices. One specific example is when a signal is an audio signal. Noise coupled onto an audio signal can be readily apparent to the user of an electronic device in many cases. Specifically, when the noise coupled to an audio signal creates audible noise to output from a speaker, the noise adversely effects the performance of the mobile handset for the user.
It would generally be advantageous to find a way to lower the signal count on the connectors of an electronic device. It would also generally be advantageous to limit noise coupling onto signal lines. Generally, limiting noise coupling onto signal lines while also lowering signal count may lower cost and improve the performance of electronic devices.